diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 9b26800..55d54a3 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1,126 +1,213 @@
 module BSC_Tests {
 
 import from Osmocom_Types all;
-
+import from GSM_Types all;
 import from IPL4asp_Types all;
 
+import from BSSAP_Adapter all;
+import from BSSAP_CodecPort all;
+import from BSSMAP_Templates all;
 import from IPA_Emulation all;
+import from IPA_Types all;
+import from RSL_Types all;
 
-import from MTP3asp_Types all;
+import from RSL_Tests all;
 
-import from SCCP_Types all;
-import from SCCPasp_Types all;
-import from SCCP_Emulation all;
-
-import from MSC_Simulation all;
-import from BTS_Simulation all;
-
-const integer NUM_MSC := 1;
 const integer NUM_BTS := 1;
+const float T3101_MAX := 12.0;
 
-type record MscState {
-	MSC_CT MSC,
-	MSC_SCCP_MTP3_parameters sccp_pars,
-	SCCP_PAR_Address sccp_addr_own
-}
-
-type record BtsState {
-	BTS_CT BTS
-}
-
-type component test_CT {
-	var MscState msc[NUM_MSC];
-	var BtsState bts[NUM_BTS];
+type component test_CT extends BSSAP_Adapter_CT {
+	var IPA_Client bts[NUM_BTS];
+	port IPA_RSL_PT IPA_RSL[NUM_BTS];
 
 	var boolean g_initialized := false;
-	var octetstring g_sio := '83'O;
+	timer T_guard := 30.0;
+
 }
 
 modulepar {
-	PortNumber mp_msc_port := 5000;
-	charstring mp_msc_ip := "127.0.0.1";
-
-	charstring mp_sccp_service_type := "mtp3_itu";
-
-	integer mp_bsc_pc := 196;
-	integer mp_bsc_ssn := 254;
-
-	integer mp_msc_pc := 185;	/* 0.23.1 */
-	integer mp_msc_ssn := 254;
-
 	charstring mp_bsc_ip := "127.0.0.1";
 	integer mp_bsc_rsl_port := 3003;
 }
 
-/* construct a SCCP_PAR_Address with just PC + SSN and no GT */
-template (value) SCCP_PAR_Address ts_SccpAddr_PC_SSN(integer pc, integer ssn) := {
-	addressIndicator := {
-		pointCodeIndic := '1'B,
-		ssnIndicator := '1'B,
-		globalTitleIndic := '0000'B,
-		routingIndicator := '1'B
-	},
-	signPointCode := SCCP_SPC_int2bit(pc, mp_sccp_service_type, '83'O),
-	//signPointCode := SCCP_SPC_int2bit(pc, mp_sccp_service_type, g_sio),
-	subsystemNumber := ssn,
-	globalTitle := omit
+type record IPA_Client {
+	IPA_Emulation_CT vc_IPA,
+	IPA_CCM_Parameters ccm_pars,
+	charstring id
 }
 
-template MTP3_Field_sio ts_sio(octetstring sio_in) := {
-	ni := substr(oct2bit(sio_in),0,2),
-	prio := substr(oct2bit(sio_in),2,2),
-	si := substr(oct2bit(sio_in),4,4)
-}
-
-template MSC_SCCP_MTP3_parameters ts_SCCP_Pars(octetstring sio, integer opc, integer dpc,
-						integer local_ssn) := {
-	sio := ts_sio(sio),
-	opc := opc,
-	dpc := dpc,
-	sls := 0,
-	sccp_serviceType := mp_sccp_service_type,
-	ssn := local_ssn
-};
-
-function f_init_MscState(inout MscState msc_st, integer opc, integer dpc, integer local_ssn, integer remote_ssn)
+function f_ipa_rsl_start(inout IPA_Client clnt, charstring bsc_host, PortNumber bsc_port, integer i)
 runs on test_CT {
-	msc_st.sccp_pars := valueof(ts_SCCP_Pars(g_sio, opc, dpc, local_ssn));
-	msc_st.sccp_addr_own := valueof(ts_SccpAddr_PC_SSN(opc, local_ssn));
+	timer T := 10.0;
+
+	clnt.id := "IPA" & int2str(i);
+	clnt.vc_IPA := IPA_Emulation_CT.create(clnt.id & "-IPA");
+	clnt.ccm_pars := c_IPA_default_ccm_pars;
+	clnt.ccm_pars.name := "Osmocom TTCN-3 BTS Simulator";
+	clnt.ccm_pars.unit_id := int2str(1234+i) & "/0/0";
+
+	map(clnt.vc_IPA:IPA_PORT, system:IPA_CODEC_PT);
+	connect(clnt.vc_IPA:IPA_RSL_PORT, self:IPA_RSL[i]);
+
+	clnt.vc_IPA.start(IPA_Emulation.main_client(bsc_host, bsc_port, "", -1, clnt.ccm_pars));
+
+	/* wait for IPA RSL link to connect and send ID ACK */
+	T.start;
+	alt {
+	[] IPA_RSL[i].receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_ID_ACK}) {
+		T.stop;
+		IPA_RSL[i].send(ts_ASP_RSL_UD(IPAC_PROTO_RSL_TRX0,ts_RSL_PAGING_LOAD_IND(23)));
+		}
+	[] IPA_RSL[i].receive { repeat }
+	[] T.timeout {
+		setverdict(fail, "Timeout waiting for ASP_IPA_EVENT_ID_ACK");
+		self.stop;
+		}
+	}
+}
+
+function f_sleep(float seconds) {
+	timer T := seconds;
+	T.start;
+	T.timeout;
+}
+
+altstep as_Tguard() runs on test_CT {
+	[] T_guard.timeout { setverdict(fail, "Timeout of T_guard"); }
 }
 
 function f_init() runs on test_CT {
 	var integer i;
-	var charstring id;
 
-	for (i := 0; i < NUM_MSC; i := i+1) {
-		f_init_MscState(msc[i], mp_msc_pc +i, mp_bsc_pc, mp_msc_ssn, mp_bsc_ssn);
-		msc[i].MSC := MSC_CT.create;
-		id := "MSC" & int2str(i);
-		msc[i].MSC.start(MSC_Simulation.main(mp_msc_ip, mp_msc_port + i, msc[i].sccp_pars, msc[i].sccp_addr_own, id));
+	if (g_initialized) {
+		return;
 	}
+	g_initialized := true;
+
+	/* Call a function of our 'parent component' BSSAP_Adapter_CT to start the
+	 * MSC-side BSSAP emulation */
+	f_bssap_init("VirtMSC");
+
+	f_sleep(5.0);
 
 	for (i := 0; i < NUM_BTS; i := i+1) {
-		bts[i].BTS := BTS_CT.create;
-		id := "BTS" & int2str(i);
-		bts[i].BTS.start(BTS_Simulation.main(mp_bsc_ip, mp_bsc_rsl_port, id));
+		f_ipa_rsl_start(bts[i], mp_bsc_ip, mp_bsc_rsl_port, i);
 	}
+	f_sleep(0.5);
 
+	T_guard.start;
+	activate(as_Tguard());
 }
 
-testcase TC_recv_dump() runs on test_CT {
-	var integer i;
-	timer T := 30.0;
+function f_exp_ipa_rx(integer bts_nr, template RSL_Message t_rx, float t_secs := 2.0, IpaStreamId sid := IPAC_PROTO_RSL_TRX0)
+runs on test_CT return RSL_Message {
+	var ASP_RSL_Unitdata rx_rsl_ud;
+	timer T := t_secs;
+
+	T.start;
+	alt {
+	[] IPA_RSL[bts_nr].receive(tr_ASP_RSL_UD(sid, t_rx)) -> value rx_rsl_ud {
+		T.stop;
+		}
+	[] IPA_RSL[bts_nr].receive { repeat; }
+	[] T.timeout { setverdict(fail, "Timeout expecting ", t_rx); }
+	}
+	return rx_rsl_ud.rsl;
+}
+
+function f_ipa_tx(integer bts_nr, template RSL_Message t_tx, IpaStreamId sid := IPAC_PROTO_RSL_TRX0)
+runs on test_CT {
+	IPA_RSL[bts_nr].send(ts_ASP_RSL_UD(sid, t_tx));
+}
+
+
+testcase TC_chan_act_noreply() runs on test_CT {
+	var BSSAP_N_UNITDATA_ind ud_ind;
 
 	f_init();
+	f_bssap_reset();
 
-	alt {
-		[] msc[0].MSC.done { }
-		[] T.timeout { setverdict(fail); }
-	}
+	IPA_RSL[0].send(ts_ASP_RSL_UD(IPAC_PROTO_RSL_TRX0,ts_RSL_CHAN_RQD('23'O, 23)));
+	f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_CHAN_ACTIV));
+	setverdict(pass);
 }
 
+/* CHAN RQD -> CHAN ACT -> CHAN ACT ACK -> RF CHAN REL */
+testcase TC_chan_act_ack_noest() runs on test_CT {
+	var RSL_Message rx_rsl;
+
+	f_init();
+	f_bssap_reset();
+
+	/* Send CHAN RQD and wait for allocation; acknowledge it */
+	f_ipa_tx(0, ts_RSL_CHAN_RQD('23'O, 23));
+	rx_rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_CHAN_ACTIV));
+	var RslChannelNr chan_nr := rx_rsl.ies[0].body.chan_nr;
+	f_ipa_tx(0, ts_RSL_CHAN_ACT_ACK(chan_nr, 23));
+
+	/* expect BSC to disable the channel again if there's no RLL EST IND */
+	rx_rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_RF_CHAN_REL), T3101_MAX);
+
+	setverdict(pass);
+}
+
+/* Test behavior if MSC never answers to CR */
+testcase TC_chan_act_ack_est_ind_noreply() runs on test_CT {
+	var RSL_Message rx_rsl;
+
+	f_init();
+	f_bssap_reset();
+
+	/* Send CHAN RQD and wait for allocation; acknowledge it */
+	f_ipa_tx(0, ts_RSL_CHAN_RQD('23'O, 23));
+	rx_rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_CHAN_ACTIV));
+	var RslChannelNr chan_nr := rx_rsl.ies[0].body.chan_nr;
+	f_ipa_tx(0, ts_RSL_CHAN_ACT_ACK(chan_nr, 23));
+
+	var octetstring l3 := '00010203040506'O
+	f_ipa_tx(0, ts_RSL_EST_IND(chan_nr, valueof(ts_RslLinkID_DCCH(0)), l3));
+
+	BSSAP.receive(tr_BSSAP_CONNECT_ind(?, ?, tr_BSSMAP_ComplL3(l3)));
+
+	/* expect BSC to disable the channel again if there's no response from MSC */
+	rx_rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_RF_CHAN_REL), T3101_MAX);
+
+	setverdict(pass);
+}
+
+/* Test behavior if MSC answers with CREF to CR */
+testcase TC_chan_act_ack_est_ind_refused() runs on test_CT {
+	var BSSAP_N_CONNECT_ind rx_c_ind;
+	var RSL_Message rx_rsl;
+
+	f_init();
+	f_bssap_reset();
+
+	/* Send CHAN RQD and wait for allocation; acknowledge it */
+	f_ipa_tx(0, ts_RSL_CHAN_RQD('23'O, 23));
+	rx_rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_CHAN_ACTIV));
+	var RslChannelNr chan_nr := rx_rsl.ies[0].body.chan_nr;
+	f_ipa_tx(0, ts_RSL_CHAN_ACT_ACK(chan_nr, 23));
+
+	var octetstring l3 := '00010203040506'O
+	f_ipa_tx(0, ts_RSL_EST_IND(chan_nr, valueof(ts_RslLinkID_DCCH(0)), l3));
+
+	BSSAP.receive(tr_BSSAP_CONNECT_ind(?, ?, tr_BSSMAP_ComplL3(l3))) -> value rx_c_ind;
+	BSSAP.send(ts_BSSAP_DISC_req(rx_c_ind.connectionId, 0));
+
+	/* expect BSC to disable the channel */
+	rx_rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_RF_CHAN_REL), T3101_MAX);
+
+	setverdict(pass);
+}
+
+
+
 control {
-	execute( TC_recv_dump() );
+	execute( TC_chan_act_noreply() );
+	execute( TC_chan_act_ack_noest() );
+	execute( TC_chan_act_ack_est_ind_noreply() );
+	execute( TC_chan_act_ack_est_ind_refused() );
 }
 
 }